Manufacture of compounds of the anthraquinone series



Patented Nov; '2', 19220 I UNITED STATES 1,434,980 PATENT OFFICE.

FREDERICK WILLIAM ATACK, OF MANCHESTER, ENGLAND, ASSIGNOR TO THE BRITISHALIZARINE COMPANY LIMITED, OF MANCHESTER, LANCASTER, ENGLAND.

MANU FACTURE OF COMPOUNDS THE ANTHRAQUINONE SERIES.

No Drawing.

To all whom it may concern:

Be it known that I, FREDERICK WILLIAM ATAoK, residing at Trafi'ord Park,Manchester, in the county of Lancaster, En land, have invented certainnew and usefu Improvements in the Manufacture of Compounds of theAnthraquinone Series, of which the following is a specification.

This invention relates to the manufacture of compounds of theanthraquinone series containin a fi-halogen substituent.

In German atent #275299 it is stated that a-brom-aminoanthraquinones areconverted into [5 derivatives in cases where a (5 position is vacant inthe ortho position with respect to the amino group. The reaction wasstated to occur on heating dry or in presence of a suitable medium suchas sulphuric acid, phosphoric acid or zinc chloride,

I have discovered that it is possible to effect a change of orientationin the case of other anthraquinone derivatives, more particularlychlorinated anthraquinones or their derivatives of various kinds andcertain brominated anthraquinones or their derivatives. I

The process according to my invention consists in the use of a specificreagent, viz., concentrated sulphuric acid at a high temperature, e. g.,in the neighbourhood of 200 C. or for a longer time at a lowertemperature. The oz-halogen derivatives are heated with such acidwhereupon [i-ha'logen derivatives are formed. Concentrated su l-' phuricacid is used to include oleum also, whichcan be employed whensimultaneous isomerization and sulphonation or oxidation is desired. 7

The invention also includes cases in which the actual chlorination ofthe anthraqu-inone is performed in presence of the hot sulphuric acid sothat the oz-halogen derivative is not isolated even if it is formed." Ifit is necessary to add a chlorine carrier such as iodine, suitableprecautions must be taken to ensure that a suflicient amount of thecarrier is present in spite of the high temperature used.

This reaction is not a mere extension of the process described in theGerman patent because I find that in the case of chlor compounds forexample, as to which nothing is described in the German patent thereaction is specific to sulphuric acid and it Serial No. 453,358.

does not appear to proceed in presence of phosphoric acid or zincchloride or by heatmg the product alone. All these methods are given asalternatives in the German patent which treats only of thebromo-comounds. I further find that the reaction oes not proceed inboiling nitrobenzene solution. he roposals of the German patent were connod to a-brom derivatives of aminoanthraquinones, as indicated above andno extension of the reaction was suggested. Moreover, the German patentdefinitely states that there must be an unoc cupied position which isortho with respect to the amino group. Such a definition clearlyexcludes the possibility of applying the reaction to bodies which do notcontain an amino roup, audit also excludes cases in which t e amino grouis in a different nucleus to the halogen group.

I have discovered the conditions in which it is possible to extend thereaction. These are (a) the use of the specific reagent, sulphuric acid,and (b) the treatment of chlor-bodies (whether containing an amino groupor not) or brom-bodies not containing an amino group in the same nucleusas the bromine atom, provided that a (5 position is vacant which is inthe meta position to the halogen substituent, with certain exceptionsenumerated below.

In all cases it appears that the halogen group is found finally in themeta position with respect to its original position and therefore theinvention is only applicable to those o-halogen compounds which containthe meta-position free which meta position is also a (5 position; the Qpositions of the anthraquinone nucleus are those numbered 2, 3, 6 and 7.

As regards chlor-compounds, the reaction is applicable tochloranthraquinones whether containing other substituents or not, forinstance sulpho groups or amino groups. I give a series of examples ofthe process, but in applying the reaction to any other body, experimentis necessary to determine whether the chlorine group is expelled. F orinstance, I exclude bodies which are decomposed by hot sulphuric acidsuch as for instance 1. hydroxy.4:.chloranthraquinone in which thedihydroxy body is produced. Again 1.

amino.tchloroanthraquinone sulphonates but 1 literature for ,groups, e.g., sulpho groups, into compounds containing (l-halogen derivatives, orbromaminoanthraquinones in which the amino group is in a differentnucleus from that containing the bromine atom. The German'patent refersto certain a-bromaminoanthraquinones but does not suggest that thereaction is applicable to the other brom-compounds I have mentioned, andit excludes these bodies by definition.

The invention will be understood more clearly with reference to thefollowing examples:

E wample 1.

Conversion of l.chloroanthraquinone into 2.chloroanthraquinone.

50 r. of 1.chloroanthraquinone (M. P.

were heated-with 500 cc. of concentrated sulphuric acid (sp. gr. 1.84)at 200 to 205 C. for 9 hours. The mixture was poured into water andfiltered. The

product by recrystallization from acetic acid had M. P. 202 to 204(which is identical with the melting point of 2.chl'oroan- 40thraquinone prepared from anthraquinone. 2.sulphonic acid sodium salt.)On the reduction with zinc dust and ammonia, 2.chloroanthrancene of thecorrect melting point (217) is obtained.

Example 2.

Conversion of 1.5.dichloroanthraquinone into 2.6.dichloroanthraquinone.I

50 gr. of 1.5.dichloroanthraquinone were heated with 500 cc. ofconcentrated sulphuric acid (s gr. 1.84) at 200 to 220 for 7 hours. Themixture was poured into waterand filtered. The product afterrecrystallization from toluene had P. 280 to 282, which is identicalwith that given in the 1 2.6.dichloroanthraquinone'. Reduction ofthissample with zinc dust and ammonia gave a product of M. P. 252 C. andthe same product was obtained from 2.6.dichloroanthraquinonepreparedfrom anthraquinone.2.6.disulphonic sodium salt.

Eabample 3.

40 gr. of Lbromanthraquinone (M. P. 184) were heated with 250 cc. ofconcenconcentrated su trated sulphuric acid (sp. gr. 1.84) at 215 to 220C. for 6 hours. The mixture was poured into water, filtered, and theprecipitate washed with dilute caustic soda. The

residue on recrystallizing from acetic acid proved to-be2.bromoanthraquinone of M. P. 201 C.

uct cr stallized from acetic acid roved to be 2.7. ichloroanthraquinoneof M. 224 C.

Example 5,

50 gr. of the sodium saltof llchloroanthraquinone.5.sulphonic acid wereheated with 250 cc. concentrated sulphuric acid (s'p. gr. 1.84) at 215to 220 C. for 5 hours. After separating the sulphonic acid produced itwas dissolved in. water and the sulphonic acid group replaced bychlorine by means of hydrochloric acid and sodium chlorate and adichloroanthraquinone of melting point 190 C. was produced. As themelting point of 1.5.dichloroanthraquinone is 251 C. it

may be assumed that the oz-chloro-compound had been completely or partlyconverted into the fi-chloro.

E trample 6.

50 gr. of 1.amino.5.chloroanthraquinone (M. P. 210 C.) were heated with200 cc. phuric acid (sp; gr. 1.84) for 5 hours at 200 to 220 C. Theproduct which was insoluble in dilute caustlc soda was isolated-in theusual manner and on recrysallizing from acetic acid had M. P. of 180 Thewords halogen derivatives or chlor derivatives of anthraquinone includederivatives containing more than one halogen atom or containingl othersubstituents such as ammo or sulp 0 groups, unless these, expressionsare specifically limited.

I declare that what I claim is:

1. The process of .treating oz-halogen derivatives of anthraquinonecontaining at least one halogen substituent in a benzene nucleus unoccuied by an amino group and having an unsu stituted {5 position which ismeta to the halogen, to convert them into fl-halogen derivatives, whichincludes the step of heating such an a-halogen derivative to a hightemperature in presence of concentrated sulphuric acid.

2. The process of treating a-halogen derivatives of anthraquinonecontaining more than one halogen substituent of which at least one is inand position and having an unsubstituted {5 position which is meta tothe halogen to convert such an oz-halogen derivative into {5 halogensubstituent in the asaeeo g;

a position derivatives, which includes the step of heating them to ahigh temperature in presence of concentrated sulphuric acid.

'3. The process of treating a derivative of anthraquinone containing atleast one chlorine atom in the a: position and having an unsubstituted[5 position which is meta to the chlorine atom, to convert it into afi-chlor derivative, which includes the step of heating it to a hightemperature in presence of concentrated sulphuric acid.

4. The process of treating a derivative of anthraquinone containing morethan one chlorine atom of which at least one is in the a position andhaving an unsubstituted (5 position which is meta to the chlorine atomin the a position, to convert it into a fi-chlor derivative, whichincludes the step of heating it to a high temperature in presence ofconcentrated sulphuric acid.

5. The process of treating a derivative of aminoanthraquinone containingat least one chlorine atom in the a position and having an unsubstitutedB position which is meta to said chlorine atom, to convert it into afl-chlor derivative, which includes the step of heating it to a hightemperature in presence of concentrated sulphuric acid.

6. The process of obtaining a fi-chlor derivative ofafdichloroanthraquinone having at least one of its chlorine atoms in ana position, and an unsubstituted '{5 position meta to one of saidchlorine atoms, in which one step of the process consists in heattreatment of such dichloroanthraquinone in derivative to about 200 C. in

presence of concentrated sulphuric acid at a hi h temperature. 7

The process of treating a-halogen derivatives of anthraquinonecontaining at least one halogen substituent in a benzene nucleusunoccupied by an amino group and having an unsubstituted (5 positionwhich is meta tosaid halogen substituent to convert them into B-halogenderivatives, which includes the step of heating such an oz-halogenpresence of concentrated sulphuric acid.

8. The process of treating a derivative of anthraquinone containing atleast one chorine atom in the a position and having an unsubstituted {5position which is meta to said chlorine atom, to convert it into afi-chlor derivative, which includes the step of heating it to about 200C. in presence. of concentrated sulphuric acid.

9. The process of obtaining fi-halogen derivatives of a dihalogenanthraquinone containing at least one halogen atom in an a position andhaving an unsubstituted {5 position meta thereto, in which one step ofthe process consists in heat treatment in presence of sulphuric acid ata high temperature. In witness whereof, I have hereunto signed my namethis 2 da of March, 1921, in the presence of two su scribing witnesses.

